Generally, solderable elastic electric contact terminals must have high electrical conductivity and excellent elastic resilience and must be resistant to a soldering temperature.
Related art reflow-solderable electric contact terminals are formed mainly of metal. Specifically, beryllium copper is widely used for the electric contact terminals because it has excellent elastic resilience and high electrical conductivity. For example, a beryllium copper sheet, having a thickness of about 0.3 mm or less and a predetermined width, is blanked with a press mold to have a predetermined shape, and then is heat-treated to form the electric contact terminal having an improved elastic resilience.
However, the electric contact terminals formed of only the metal sheet, because of metal characteristics or structures, cannot provide excellent elasticity in a predetermined height or less. To increase the elasticity, the metal sheet must be bent in a predetermined shape to have a bent height that mainly determines the height of the electric contact terminal, so that the electric contact terminal cannot provide elasticity in a predetermined height or less. In addition, since a single press mold can form products having an identical shape, additional expensive press molds are needed to form products having different shapes. Furthermore, the light-weight electric contact terminal formed of a metal sheet can be moved by the wind supplied in a surface mounting process, thereby causing defect.
Another related art is disclosed in EP Patent EP 1090538 issued to Gore Enterprise Holdings Inc (US). According to this patent, an additional adhesive is needed to fix an electrically conductive gasket material and a solderable support layer, thereby causing inconvenience. Furthermore, the adhesive increases electric resistance.
Further another related art is disclosed in U.S. Pat. No. 7,129,421 issued to the Gore Enterprise Holdings Inc (US). According to this patent, a compression hole is provided to an electrically conductive gasket material, and an electrically conductive support layer, that goes through a crimp process, is provided to a bottom surface of the electrically conductive gasket material, thereby reducing the productivity of electromagnetic interference (EMI) gasket assemblies. That is, after the electrically conductive gasket material is manufactured, the electrically conductive support layer, that is separately manufactured, is inserted into the compression hole of the electrically conductive gasket material and then pressed, thereby causing inconvenience. The compression hole has a smaller size than the EMI gasket assembly. Hence, a size of the electrically conductive support layer in the compression hole is limited thereby, so that an adhesive force is not sufficient between the electrically conductive gasket material and the electrically conductive support layer. That is, when the EMI gasket assembly is drawn in an upper direction, the electrically conductive gasket material is easily removed from the electrically conductive support layer.